Piston device for dispensing controlled amounts of pasty substances

ABSTRACT

A piston device for dispensing controlled amounts of pasty substances, such as ice creams, that is connectable to the freezing chamber of an ice cream making machine. Said device comprises a cylindrical closing element mounted rotatably about its axis in a mating cradle support, recessed into which cylindrical closing element is a cylinder that extends diametrically across said closing element and is closed at the bottom by a wall containing a hole, while a piston slides axially inside the said cylinder, and in which the said cradle support contains a communicating channel leading to the freezing chamber of the ice cream making machine, so that in one angular position of the cylindrical closing element the channel of the support is lined up with the hole of the bottom wall, while in a second angular position of the cylindrical closing element the hole of the bottom wall of the cylinder is lined up with a dispensing hole provided in the said cradle support, while the side wall of the cylindrical closing element is provided with an elongate passage which in a third position of the cylindrical closing element connects together the feed hole and the dispensing hole of the support, bypassing the said cylinder.

BACKGROUND AND SUMMARY OF THE INVENTION

The present invention relates to devices for dispensing pastysubstances, such as ice creams for example, that is connectable to themachines that make the said substances.

More particularly, the invention relates to a piston device fordispensing ice creams in predetermined quantities, which device isconnectable to the closing door of the freezing chamber of an ice creammaking machine, preferably a soft ice cream making machine of the“self-service” type operated automatically by coins or tokens.

Ice cream dispensers are known consisting of a dosing piston device (seefor example Austrian Patent No. 257332 of 14.9.1965) that basicallycomprises a cylinder containing an axially sliding expulsion piston anda counter-piston, between which a measuring chamber is formed when theexpulsion piston is raised, this chamber being filled with the ice creamcoming from the freezing chamber of an ice cream making machine, afterwhich both pistons are slid axially with the volume of ice cream heldbetween them until the counter-piston meets a stop, such that furthermovement of the expulsion piston expels the volume of ice creamcontained between the piston and the counter-piston through a dispensingport.

These known devices are mechanically complex, are difficult to adjustwhen it is wished to change the amount of product dispensed, and aboveall are difficult to maintain and to clean.

The object of the present invention is therefore to provide a pistondevice for dispensing controlled amounts of pasty substances,particularly ice creams, that can be connected to the door of thefreezing chamber of an ice cream making machine, in such a way as toovercome the drawbacks and disadvantages of known piston devices thatdeliver metered amounts of substance.

In accordance with one feature of the present invention, the dispensingdevice delivers metered amounts of substance comprises a cylindricalclosing element mounted rotatably about its axis in a mating cradlesupport, recessed diametrically into which cylindrical closing elementis a cylindrical housing (hereinafter abbreviated to “cylinder”) that isclosed at the bottom by a wall containing a hole, while a piston slidesaxially inside the said cylinder, and in which the said cradle supportcontains a communicating hole leading to the freezing chamber of the icecream making machine, so that in one angular position of the saidcylindrical closing element the said hole of the support is lined upwith the hole of the bottom wall of the said cylinder, while in a secondangular position of the said cylindrical closing element the said holeof the bottom wall of the cylinder is lined up with a dispensing holeprovided in the said cradle support, while the side wall of the saidcylindrical closing element is provided with an elongate passage whichin a third position of the said cylindrical closing element connectstogether the feed hole and the dispensing hole of the support, bypassingthe said cylinder.

BRIEF DESCRIPTION OF THE DRAWINGS

Other features and advantages of the present invention will becomeclearer in the following detailed description of a preferred embodimentof the present invention, illustrated in the appended drawings, inwhich:

FIG. 1 shows in longitudinal section the device according to theinvention connected to the door of a freezing chamber, in the operatingposition in which the ice cream is fed into the metering cylinder. Thecylindrical closing element of the device according to the invention hasbeen rotated into this position about its transverse axis so that thehole in the bottom of the metering cylinder is lined up with the icecream feed hole;

FIG. 2 is a view similar to FIG. 1, in which the cylindrical closingelement of the device according to the invention has been rotated untilthe hole in the bottom of the metering cylinder is lined up with the icecream dispensing hole of the door, at the same time closing the icecream feed hole;

FIG. 3 is a view similar to FIGS. 1 and 2, in which the cylindricalclosing element of the device according to the invention has beenrotated until a passage formed in its side wall is simultaneouslysuperimposed over the ice cream feed hole and the ice cream dispensinghole, connecting them together directly, and

FIG. 4 is a plan view from below of the device shown in the previousFIGS. 1 to 3.

DESCRIPTION OF THE PREFERRED EMBODIMENTS OF THE INVENTION

Referring to the drawings, and with particular reference to FIG. 1thereof, the number 1 denotes the freezing chamber of an ice creammaking machine, of which only the front end is visible. This chamber iscooled, in a known manner, by the evaporator (not shown) of arefrigerating circuit, and is equipped with an internal stirrer/mixer(also not shown).

The chamber 1 is closed at the front end by the door 2 which houses thedispensing piston device according to the invention. As illustrated inlongitudinal section in FIG. 1, the door 2 comprises a base 102 that isattached leaktightly by suitable fixing means (not shown) to the end ofthe chamber 1, and a part 202 in which a cylindrical cradle housing 302is formed that extends around an angle of slightly less than 180°. Thebase 102 contains a channel 402 that communicates on one side with thechamber 1, while on the other side it ends in the hole 502 that opensinto the housing 302. A second hole 602 is provided at a short distancedownstream, in the clockwise direction, of the said hole 502 andcommunicates on one side with the housing 302, while on the other sideit communicates with the exterior, forming the ice cream dispensinghole.

The cylindrical closing element 3, the diameter of which iscomplementary to the diameter of the housing 302, is mounted inside thehousing 302 such that it can rotate about its axis. The cylindricalclosing element 3 contains a cylinder 4 whose axis, which isperpendicular to the axis of the closing element 3, extendsdiametrically across the said cylindrical closing element 3. Thiscylinder 4 is open at its end furthest from the housing 302, while atits other end it is closed by a wall 104 containing a hole 204 that iseccentric with respect to the axis of the cylinder 4.

A sliding piston 5 is mounted inside the cylinder 4, which piston isprovided with a hemispherical crown with a radius of curvature that isthe same as the radius of curvature of the bottom wall 104, and isprovided with an eccentric circular button 105 that projects outwardsand is complementary to the hole 602 (FIG. 2). The piston 5 is providedwith a control rod 6, projecting radially outwards from which is a pin106 capable of being engaged in a slot 206 formed in the inside wall ofthe cylinder 4 along one of the generatrices of the said cylinder, forpurposes which will be described later.

In addition, there is formed on the cylindrical side wall of the closingelement 3 an elongate passage 7 capable of connecting together the holes502 and 602, as will be described later.

Lastly, as shown more clearly in FIG. 4, there is formed in the bottomof the door 2, all the way around the ice cream dispensing hole 602, anessentially U-shaped channel 8 that surrounds the said hole 602, whichchannel receives the pair of tubes 9 belonging to the evaporator (notshown) of the refrigerating circuit which surrounds the side wall of thefreezing chamber 1.

The device described works in the following manner.

It is assumed that the device is in its initial position, or restposition, illustrated in FIG. 2. In this position the cylindricalclosing element 3 closes the ice cream G feed port 502, while the piston5 has been pushed all the way down into the cylinder 4, and the surfaceof its crown is in contact with the bottom of this cylinder, with theelement 105 inserted into the dispensing hole 602 and closing it. Thepin 106 has been guided all the way down to the bottom of the slot 206.The job of this pin is to position the eccentric element 105 correctlywith respect to the equally eccentric dispensing hole 602.

If it is wished to dispense a serving of ice cream, the cylindricalclosing element 3 is rotated in the direction of arrow F1 until the hole204 of the cylinder 4 is lined up with the ice cream feed hole 502 (therelative position seen in FIG. 1). The ice cream G, pushed by thestirrer inside the freezing chamber 1 (the stirrer is started when theelement 3 is rotated) passes through the holes 502 and 204 and fills thecavity of the cylinder 4 downstream of the piston 5, which is thereforepushed up in the direction of arrow F2. The upward movement of thepiston 5 is limited for example by suitable stop means (not shown)engaging with the rod 6 of the piston itself, the precise position ofwhich determines the “serving” of ice cream fed into the cylinder 4 inthe course of the phase described above.

At this point, the cylindrical closing element 3 with its serving of icecream is moved to the position shown in FIG. 2 by rotating it in thedirection of arrow F3 until the port 204 is lined up with the port 602.At the same time the feed port 502 is closed by the wall of the closingelement 3. At this point the piston 5 is pushed down inside the cylinder4 in the direction of arrow F4 so that the serving of ice creamcontained in the cylinder 4 is expelled through the dispensing hole 602.At the end of this stage the element 105 passes into the hole 602,expelling any residues of ice cream from it. At the end of this stagethe device is returned to the position shown in FIG. 2, ready todispense another serving of ice cream. Because of the presence of thechannel 8 supplied with the refrigerating fluid of the evaporator 9, theregion of the dispensing nozzle 602 is maintained at an optimaltemperature, eliminating or greatly reducing the dripping that usuallyoccurs in this area.

FIG. 3 illustrates a particular condition of the door according to theinvention. At the end of a working day, or whenever it is desired towash both the freezing chamber and all the parts of the dispensingpiston assembly through which the ice cream passes, the followingprocess is carried out.

With the cylindrical closing element 3 in the rest position shown inFIG. 2, it is rotated to the position shown in FIG. 3, in the clockwisedirection (arrow F3), until the channel 7 running through thecylindrical side wall of the closing element 3 reaches the position inwhich it connects together the hole 502 and the hole 602 (position shownin FIG. 3). When the stirrer inside the freezing chamber 1 is nowstarted, all residual ice cream present in the freezing chamber 1 isemptied out, to be collected in a suitable container (not shown). Atthis point, the piston having returned to the position shown in FIG. 2,a washing mixture is introduced into the freezing chamber 1, then alsopassed into the cylinder 4 by positioning the closing element 3 in theposition shown in FIG. 1, after which the closing element 3 is movedinto the position shown in FIG. 2, causing the washing solution to bedrained from the cylinder 4. The cylindrical closing element 3 is thenmoved into the position shown in FIG. 3 so that all of the washingmixture is drained out. If necessary, these steps are repeated asrequired, thus washing and completely sanitizing all parts in the flowline of the ice cream.

Naturally, the operation of the piston 5 rod, and consequently therotation of the closing element 3 and the raising and lowering of thepiston 5, may be effected by any mechanical device capable of causingthe rod 6 of the piston to move translationally and rotationally alongor about two orthogonal axes. It may of course also be effectedmanually, although the present device was mainly designed for use inautomatic machines.

The present invention is therefore not limited to the embodimentillustrated and described but encompasses all those modifications andvariants that come within the more general scope of the invention,essentially as claimed below.

I claim:
 1. Piston device for dispensing controlled amounts of pastysubstances, such as ice creams, that is connectable to the freezingchamber of an ice cream making machine, comprising a cylindrical closingelement mounted rotatably about its axis in a mating cradle support,recessed into which cylindrical closing element is a cylinder thatextends diametrically across the said closing element and is closed atthe bottom by a wall containing a hole, while a piston slides axiallyinside the said cylinder, and in which the said cradle support containsa communicating hole leading to the freezing chamber of the ice creammaking machine, so that in one angular position of the said cylindricalclosing element the said hole of the support is lined up with the holeof the bottom wall of the said cylinder, while in a second angularposition of the said cylindrical closing element the said hole of thebottom wall of the cylinder is lined up with a dispensing hole providedin the said cradle support, while the side wall of the said cylindricalclosing element is provided with an elongate passage which in a thirdposition of the said cylindrical closing element connects together thefeed hole and the dispensing hole of the support, bypassing the saidcylinder.
 2. Device according to claim 1, in which the said dispensingpiston device is part of a door closing the freezing chamber of an icecream making machine, the said door comprising a base that is attachedleaktightly by suitable fixing means to the end of the chamber, and apart in which said cylindrically profiled cradle housing is formed. 3.Device according to claim 2, characterized in that he base of the saiddoor contains a channel that communicates on one side with the chamber,while on the other side it ends in a first hole that opens into thehousing.
 4. Device according to claim 3, in which a second hole isprovided at a short distance downstream of the said first hole andcommunicates on one side with the said housing, while on the other sideit communicates with the exterior, forming the ice cream dispensinghole.
 5. Device according to claim 4, in which the said cylindricalclosing element is mounted rotatably inside the said housing.
 6. Deviceaccording to claim 5, in which the said cylindrical closing elementcontains a cylinder whose axis, which is perpendicular to the axis ofthe said closing element, extends diametrically across the saidcylindrical closing element, the said cylinder being open at its endfurthest from the housing, while at its other end it is closed by a wallcontaining a hole.
 7. Device according to claim 6, in which the saidhole of the said cylindrical closing element is eccentric with respectto the axis of the said cylinder.
 8. Device according to claim 7, inwhich a sliding piston is mounted inside the said cylinder.
 9. Deviceaccording to claim 8, in which the said piston is provided with a crownwith a radius of curvature that fits the radius of curvature of thebottom wall of the said cylinder.
 10. Device according to claim 9, inwhich the said piston crown is provided with a circular button, thatprojects outwards and is complementary to the hole in which it canengage.
 11. Device according to claim 10, in which the said piston isprovided with a control rod, projecting radially outwards from which isa pin capable of being engaged in a slot formed in the inside wall ofthe said cylinder along one of the generatrices of the said cylinder.12. Device according to claim 11, in which there is formed on thecylindrical side wall of the closing element an elongate passage capableof directly connecting together said first and second holes and whichrespectively feed and dispense the ice cream.
 13. Device according toclaim 12, in which there is formed in the bottom of the said door, allthe way around the ice cream dispensing hole, an essentially U-shapedchannel that surrounds the said hole, the said channel being connectedto the evaporator circuit of the refrigerating system of the freezingchamber.